Vaned hydraulic unit



Dec. 5, 1961 w. ERNST VANED HYDRAULIC UNIT INVENTOR.

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3 Sheets-Sheet 1 Filed April 15, 1960 w. ERNST VANED HYDRAULIC UNIT Dec.5, 1961 5 Sheets-Sheet 2 Filed April 15, 1960 Dec. 5, 1961 w. ERNSTVANED HYDRAULIC UNIT Filed April 15, 1960 3 Sheets-Sheet- 5 INVENTOR.

' W417i? [EA/ST ZwAm/M United States Patent Ofifice 3,011,449 PatentedDec. 5,-1961 Ohio Filed Apr. 15, 1960, Ser. No. 22,566 3 Claims. (Cl.103136) This invention relates to hydraulic pumps and motors and isparticularly concerned with an improved construction for hydraulic pumpsand motors'which will operate at increased efiiciency over heretoforeknown hydraulic units of this nature.

Hydraulic pumps and motors are fluid displacement units substantiallyinterchangeable and one well known type of hydraulic pump or motor isthe type utilizing vanes mounted in a slotted rotor with the rotorrotating inside a stator. It is in connection with this particular typeof hydraulic unit that the present invention is concerned.

Vane type hydraulic units have certain inherent disadvantages overpiston type units in that in the usual vane type unit the vanes slidecontinuously over the surface of the bore in the stator in which therotor is mounted thus leading to considerable friction and thepossibility of the tips of the vanes or the inside of the stator gallingor there being wear at an unduly high rate.

Another disadvantage encountered in connection with vaned type hydraulicunits is that the projected area of the rotor and stator under pressureis quite large thus leading to extremely high thrusts on the stator.

Having the foregoing in mind, it is a primary object of the presentinvention to provide a vaned hydraulic unit such as a pump or motor inwhich the friction between the vanes and the stator surface over whichthey slide is greatly reduced.

A still further objectof this invention is the provision of a vaned pumpor motor unit in which the possibility of the vanes galling the insidesurface of the stator is greatly reduced.

A still furtherobject is the provision of a vaned hy-, draulic unit suchas a pump or motor in which the lateral forces on the stator on accountof pressures therein are substantially balanced out.

These and'other objects and advantages will become more apparent uponreference to the drawings in which:

FIGURE 1 is a plan view showing. a hydraulic unit according to thisinvention; 1

FIGURE 2 isan explodedperspective view showing the unit;

FIGURE 3 is a vertical sectional view indicated by line 33 on FIGURE 1;

FIGURE 4 is a transverse sectional view indicated by line 44 on FIGURE3;

FIGURE 5 is a transverse sectional view indicated by line 55 on FIGURE3; 1 1

FIGURE 6 is still another transverse sectional view indicated by line6-6 on FIGURE 3;

FIGURE? is a plan sectional view indicated by line 77 on FIGURE 5; and

FIGURE Sis a diagrammatic representation of a typical hydraulic circuitin. which a unit accordingto this invention can be placed. Y Y aReferring to the drawings more in detail, a pump or motor according .tothis invention comprises an outer body part consisting of .the heads 10and 12 andinter-v l 2 a posed therebetween is an annular center ring 14sealedto the beads by sealing rings 16. The heads are intercon: nectedby the through bolts 18.

Each head has a recess therein in. which there is mounted a wear plate20in the head 10 and 22 in the head 12. These :Wear plates are locatedby the dowel pins 24 and are ported for supplying fluid to the vanedrotor.

Positioned between plates 20 and 22 and inside ring 14 is the statorring 26 which, as will be seen in FIGURE 4, is a true ring shapedmember. Mounted in the borein stator ring 26is the rotor '28 which isradially slotted to receive the vanes 30 which bear against the innerwall of stator ring 26. 7

Both rotor 28 and stator ring 26 have a running fit between plates 20and 22 so that the stator ring can rotate with the rotor when the unitis operated.

. Rotor 28 has journal portions 31 extending therefrom in oppositedirections that 'are'supponted on the needle bearings '32 in the headsIO-and 12 I The rotor is bored through and in about the center thereofhas a splined portion 34 that engages the splined portion 36 of a driveshaft 38 that issupported on the antifriction bearings 40 in'the heads.

It will be apparent that the shaft is journalled independently of therotor'thus allowing for some slight freedom of movement between therotor and the shaft'and relieving the shaft'o-f transverse loads andpermitting'somewhat more inexpensive machining and construction than ifthe shaft and rotor were integral.

The projecting end of shaft '38 issealed to the of the unit by thesealing means at 42. r v j The unitmay be-su'pported-by a mounting ring44'bolts to head 10 andhaving a'footp'ortion 46.-

Fluid is supplied to the unit by way of the fittin'gs 48 and 50 mountedon head 12 and to which conduits-are connected that communicate throughthe fittings with-the arcuate tapering passages 52" and 54respectivelyformed inside head12 and communicating via thearcuate slots56 and 58 respectively with'the' slots-'60a., 60b and 62a, 62b in thewear plate 22. These last mer'ltion'ed-s'lots direct the fluid into'thespaces between the rotor and the stator'ring and betweenthe spacesbetween the values? The other wear plate 20' may be made substantiallyidentical with wear plate 22 and have similar 'ports therein. "z

The wear plates also comprise an annular groove 64 which is'positionedso as to communicate with the enlarged regions 67 located at the' innerends ofthe slots 69 in which'the vanes 36 stemmed; I;

The aforementioned groove 64 in at least 'wear' plate 22 'is adapted forcommunicating with passage means .66 extending laterally into head 12from the sides thereof andterminating' in the short sections d s'whichopen to the back of -,wear plate 22in the region of the. annular groove.64. V p f The drilled recesses 70in the back of wearplate 22communicate-,at their one ends with the. annular groove 64 and at theirother ends with the short passages 68 so body that communication withthesaidannular groove and thus with the enlarged spaces 61at the inner endsof the vanes can-belha'd eitherflthrough' one or both of the passages 66in head 12.

- The stator rin'g 26is supported inside the center ring it member 14onicircumfe'rentially spaced -land"areas""71" a 3 which definetherebetween chambers that are utilized for balancing the thrust on thestator ring.

In FIGURE 4, for example, at the top and bottom of the stator ring arethe chambers 72 and 74 which communicate with the slots adjacent theretoin the wear plates or side plates by the milled slots 76 and 78respectively formed in the side plates.

It will be evident that in either direction of rotation of the rotor andwith the device operating as either a pump or a motor, one of thechambers 72 and 74 will be under inlet pressure and the other will beunder discharge pressure and that the one under pressure will always beassociated with the side of the stator ring which is under internalpressure.

At the sides of the stator ring are the chambers 80 each of whichcommunicate via milled slots 82 in the side plates with passages 84formed in head 12 and which passages are interconnected and lead to adrain passage 86. The chambers 80 are thus continuously under drainpressure.

The described arrangement is utilized for fully balancing the hydraulicthrust on the stator ring due to the working pressure therein.

In one unit, for example, the stator bore is 3% in diameter and there isthus a projected area under pressure which measures 3%" transversely ofthe unit.

This is balanced oil? by making the adjacent one of the chambers 72, 74so that it has a 3 projected dimension transversely of the pump and bymaking the land areas in the opposite sides thereof so that each has adimension measured transversely of the unit.

The land areas at their ends adjacent the pressurized chamber will beunder full pressure and at their other ends will be under drain pressureso that the effectiveness of each is reduced by half so that the totalprojected area on the outside of the stator ring that is underpressurewill be exactly epual to the projected area inside the stator ring. Thestator ring thus floats inside the center member 14 and will rotate withthe stator on account of the frictional engagement of the vanes with theinside of the stator ring.

It will be understood that since the stator ring and rotor are notconcentric, there will be some slight slippage between the ends of thevanes and the inside of the stator ring but this is greatly minimizedover what occurs in units where the stator ring is not rotatable andthere is thus substantially less Wear, less frictional loss and a greatdeal less chance the surface of the stator orthe ends of the vanes willbecome galled While the unit is operating.

Due to the reduced slippage between the vanes and the stator ring it ispossible to use a higher pressure for urging the vanes outwardly withoutinducing the danger of accelerated wear and increased frictional loss.

A typical hydraulic circuit in which the unit according to the presentinvention is adapted for being used is illustrated in FIGURE 8. v

In this figure the unit according to the present invention is indicatedat 90 and it is running as a unidirectional motor with there being asupply of fluid to the unit from a pump 92.

The pump discharges through a conduit 94 and throttle valve 96 to theinlet of a spring loaded check valve 98. The discharge side ofthe springloaded check valve is connected with an open center reversing valve 100having one service'po'rt connected by conduit 102 with one side of theunit 90 while the other side of the unit 90 is connected by conduit 104through check valve 106 with the other service port or valve 100, thesaid check valve opening toward the service port.

Connected between conduits 104 and 102, is a relief valve 108 which isadapted for being piloted open by pressure conducted thereto via conduit110 from conduit 104.

The aforementioned spring loaded check valve 98 maintains apredetermined pressure in conduit 94 on the inlet 4 side of the checkvalve and this pressure is conducted by a conduit 112 to the unit and isutilized for pressurizing the inner end of the vanes. By thisarrangement, with pump 90 operating continuously, the vanes are alwayspressurized.

When valve is adjusted to run position, fluid will be delivered toconduit 102 and cause unit 90 to operate with fluid dischargingtherefrom through conduit 104 and check valve 106 to valve 100.

In the centered position of valve 100, and in which position it isillustrated in FIGURE 8, both the pump 92 and the vaned unit of thepresent invention 90 are connected to the tank and the unit 90 can thuscoast freely. The vanes at this time remain pressurized so that the unitis ready to be placed in operation instantly.

In the other position of valve 100, in which the valve member is moveddownwardly from its FIGURE 8 position, the unit 96 is braked and it willrun as a pump with fluid being discharged from conduit 104 passingthrough relief valve 108 to conduit 102. This relief valve will controlthe pressure on the discharge side of unit 90 and cause a retarding orbraking action which will slow down the unit more or less rapidlydepending on the setting of relief valve 108.

The foregoing example is merely one of the many manners of using theunit of the present invention and it will be understood that theparticular illustration where the unit runs as a unidirectional motor,is not intended in any way to limit the present invention.

It will'be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions; and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

I claim:

1. In a vaned hydraulic unit; a slotted rotor, vanes in the slots of therotor, an inner stator ring surrounding the rotor and eccentrictherewith, an outer stator ring rotata'bly supporting said inner statorring, said outer stator ring comprising axial recesses formed on theinner surface thereof at diametrically opposite positions on an axis atright angles to the axis of eccentricity of the rotor and inner statorring, each said chamber being hydraulically connected with the inside ofthe inner stator ring immediately opposite thereto, said outer ringbeing formed with exhaust chambers formed therein at diametric points onthe axis of eccentricityof the rotor and inner stator ring, land areasbetween said chambers forming the direct support of the inner statorring in the outer ring, and the area of each of saidfirst'mentionedchambers plus one-half the areas of the said land areas being equal tothe projected area of the inside of said inner stator ring that is underpressure, and end members engaging opposite sides of said outer statorring and com prising bearing means for supporting said rotor and a driveshaft therefor.

2. In a hydraulic pump or motor; a frame, a slotted rotor rotatablyjournaled in the frame, a drive shaft rotatably journaled in the frameindependently of the rotor extending through the rotor and splinedthereto, vanes in the slots of the rotor, ported side plates in theframe on opposite sides of the rotor, a stator ring rotatably supportedin the frame eccentric to the rotor and slidably fitted between the sideplates, means for supplying fluid through the side plates to the spacesbetween the vanes, means for supplying fluid to the inner ends of thevane slots for urging the vanes outwardly into engagement with the innersurface-of the stator ring, and passages in the side plates connectingthe outer surface of the stator ring at any point thereabout with theinside of the stator ring along the same radial line, said framecomprising a center ring partsurrounding and supporting said statorring.

3. In a hydraulic pump or motor; a frame, a slotted rotor rotatablysupported in the, frame, a drive shaft rotatably supported in the frameindependently of the rotor extending through the rotor and splinedthereto, vanes in the slots of the rotor, ported side plates in theframe on opposite sides of the rotor, a stator ring rotatably supportedin the frame eccentric to the rotor and slidably fitted between the sideplates, means for supplying fluid through the side plates to the spacesbetween the vanes, means for supplying fluid to the inner ends of thevane slots for urging the vanes outwardly into engagement with the innersurface of the stator ring, hydraulic bal- 10 ancing chambers in theframe around the stator ring, and passages in said side plateshydraulically connecting the chambers with the inside of the stator ringwhereby the thrusts on the stator ring from pressures inside arebalanced by equal and opposite thrusts on the outside of the stator ringso that the stator ring floats in the frame and will turn with therotor. I 7

References Cited in the file of this patent UNITED STATES PATENTS1,460,487 Hawkins July 3, 1923 2,918,877 Woodcock Dec. 29, 19592,924,182 Blasutta et al. Feb. 9, 1960 FOREIGN PATENTS 14,968 GreatBritain 1915 835,271 France Sept. 19, 1938

